A police officer is being investigated over alleged Facebook comments that spoke of looking forward to "bashing some long-haired hippies" at the G20 protests.
Pc Rob Ward could face disciplinary action by the Metropolitan Police over the message, which was apparently posted online shortly after the death of newspaper seller Ian Tomlinson.
The Facebook page was taken down, but it previously showed a message timed at 8.17pm on April 1, which read: "Can't wait to bash some long haired hippys up @ the G20."
Twenty minutes later a reply was posted that said: "LMAO (laughing my a*** off) dats bad but good in da same way lol (laugh out loud)."
A Scotland Yard spokeswoman said: "The matter has been recorded and will be investigated appropriately.
"Officers from the Directorate of Professional Standards will carry out the initial assessment."
Metropolitan Police Commissioner Sir Paul Stephenson warned that he would not accept "inappropriate conduct" by his officers.
But writing in London's Evening Standard he went on: "I do not accept that the units in the Met that handle public order and violent incidents are out of control."
The Independent Police Complaints Commission is investigating the death of Mr Tomlinson, who collapsed after a confrontation with officers during the G20 protests in the City of London on April 1.
